This invention relates to four wheeled garden tractors. More particularly it pertains to garden tractors of configurations adapted to mounting various and different implements. Still more particularly it pertains to tractors configured for mounting the implements between front and rear wheels in full unobstructed frontal and central view of a driver. A further objective, but not in a limiting sense, is a tractor fully manageable by a person with any one limb unusable.
Lawn tractors are currently marketed with rear mounted engines, usually rigged for driving lawn mowers mounted between front and rear wheels but there is a deck fitted with a steering wheel in the immediate front of the driver. Such decks are just high enough for a belly mower to be raised slightly above the usual grass cutting level. Such decks obstruct the drivers view of a row of crops over which the tractor could be moving.
On tractors specifically designed for row crops, the driver cannot steer the tractor and directly manipulate mounted implements, pull weeds, or pick selected crop products with both hands without losing control of the forward moving tractor.
Occasionally, there is a need to briefly lift vegetation clogged tilling tools for clearing of such clogging without having to manipulate levers or power lifts and without losing some lateral control of the tractor.
Attempts to control weeds in crops by tilling implements requires that some soil moving plows, discs, or sweeps move very close to the crop being served. Even brief distractions or loss of lateral control of the tractor damages crops. Many taller crops can be damaged by low clearance tractor parts. On small tractors, straight axles connecting opposing wheels are too low for taller crops, and the usual garden tractor becomes unusable after crops have a certain amount of height.
Garden tractors with little height clearance are usually replaced, when crops get taller, by some form of tilling machine that runs between taller crop rows. That usually mandates walking behind such machines and limits the area of gardens maintainable by individuals, particular older gardeners, especially during summer.
There is a need for a tractor manageable by an individual with three limbs regardless of which limb is useless or missing. This invention provides a tractor manageable as described above with little compromise of utility resulting from a missing limb. Most tractors can be adapted for use by an individual with a particular limb missing. Preferred, is a tractor as described above that will accommodate an operator with any one limb missing, without modification of the machine. Further, a tractor is needed that can be used by different individuals with different handicaps without modifying the tractor.
In some locations, noise is a disabling factor in that engine driven machines cannot be operated. Many large gardens exist under such conditions. There is a need for an options mounting deck that permits substitution of batteries and electric traction motors rather than limiting the configuration to engines.
These and other objects, advantages, and features of this invention will be apparent to those skilled in the art from a consideration of this specification, including the attached claims and appended drawings.
The four wheeled, rear engine driven, tractor has independently suspended rear wheels driven by an elevated gearbox and differential, or transaxle, for central ground clearance. The forwardly extending portion of the frame is U shaped, the closed end forward, that is attached to the rear frame portion containing the rear wheel axle supports and rises forward to clear crops. At the forward apex, a pivotable support is provided for a transverse rocking front wheel spreader and steering arrangement. The frame, on each side, supports a generally vertical steering lever with both hand grips and foot stirrups, connected by steering links to the front wheels. The front wheels are interconnected by steering control linkage to assure sympathetic steering of both front wheels. The frame has a generally central opening between the legs of the U-shaped portion of the frame, compromised minimally by the steering levers which rise above the frame on opposite sides.
The central pivot for the front wheel spreader beam is a single rod extending forward from the frame forward apex which is, preferably, of ruggedized tubular construction for stiffness. The wheel spreader beam has terminals to bearingly support vertical steering columns, that carry the caster axles of the front wheels, above the general center of the front wheels. The front wheel axles are transverse the steering columns and somewhat behind the related vertical line of steering rotation to achieve a caster effect to provide steering xe2x80x9cfeelxe2x80x9d or feedback to aid in steering control.
The generally vertical steering levers pivot at the frame level and optional foot stirrups can be selectively mounted to project inward or outward from the levers either above or below the pivot axis. The single steering lever on each side of the tractor can be exchanged for an articulating linkage that permits the foot operated portion of the steering arrangement to be separately mounted forward of the hand control portion of the levers. That divided arrangement accommodates a tall operator without causing the foot engaged portion to move in a direction with too much vertical component. The foot and hand portions of the levers are connected for simultaneous movement.
The tractor frame is shaped, and the front and rear wheel base is situated to accept plow or sweep support and control frames, lawn mower decks, and the like.
Implement mounting is arranged for convenient vertical movement between the use position and the transport position. Optional implement supported components, such as plow sweeps can be adjusted for plowing depth with the implement in the use position. Lifting to the transport position comprises a movement of the plow mounting frame such that it toggles through a compression line between pivoting components at the ends of a two-bar linkage. The implement frame acts as a part of a two bar linkage connecting two spaced pivot points on the tractor frame, and is stable in a raised state or a lowered state.
The operator seat is situated just aft of the central opening of the frame, and just ahead of the engine. Throttle, clutch and gear shift levers, preferably, project forward to riser portions that extend just above a transverse planar structure that connects the two drive wheel assemblies. The engine and transaxle are bolted to the transverse planar structure. The transverse planar structure supports the operator seat.
Drive shafts extend laterally from each end of the transaxle and each terminates in a drive sprocket positioned to carry a drive chain that turns a driven sprocket driving a respective rear wheel. Near each drive sprocket, a bearing block attached to the frame separates the drive sprocket and a brake drum secured to the drive shaft.
A brake band, anchored to the frame, is associated with each brake drum and can apply braking action to the respective drum independently in order to provide independent wheel braking.
The engine, preferably with a vertical output shaft, is connected to the transverse plate and has a vee belt drive pulley that is connected by belt to a driven vee belt pulley on the transaxle. The clutch arrangement, preferably, loosens or tightens the belt.
The clutch control lever and throttle lever are attached to the transverse plate which invites the use of adjustable friction drags. The lever movement resistance can be adjusted to suit the operator. The clutch and throttle levers can be fitted with friction locked adjustable components that permit their manual contact ends to be presented to the operator such that they can be positioned for thigh movement to throw the clutch into or out of engagement while the operators feet (or hands) steer the tractor. The throttle can be made similarly adjustable for operation with the other thigh. Alternatively, by operator choice, the clutch and throttle levers can be positioned for hand operation only.
Each brake can be operated by a manual lever. Optionally, the brake linkage is associated with the steering linkage such that extreme turning positions of the front wheels are associated with brake application of the drive wheel nearest the center of the turning radius involved. Manual operation of each brake is facilitated by levers on the brake related side of the operator.
The various features listed above are not to be viewed in a limiting sense. They are features made convenient by the general layout of the tractor principal structure. Individually, most features cited can be substantially changed without compromising the overall operational nature of the tractor. This is anticipated by and is within the scope of the claims.